Emergencies - Renal failure
If both kidneys are blocked then it can rapidly lead to renal failure. There can be very low to absent urine output (anuria). The conditions that can lead to this serious problem, even in the newborn period, include
Posterior Urethral Valves
Ureterocele blocking bladder outlet
They need to be carefully treated by experts in the field. Some times a simple catheter can revert the situation. Dialysis may be required before planning definitive surgery. Both of these problems can be tackled by a simple endoscopic surgery, relieving the blockage.